Haenel, working with the choreographer-director Gisèle Vienne in “L’Étang,” is trying to “pierce through the surface of things.”The actress Adèle Haenel bristled when asked what drew her to radical art and politics. “The term ‘radical’ is used as a way to discredit protest discourse,” said Haenel, who is best known in the United States for the 2019 art-house hit “Portrait of a Lady on Fire.” That was also one of the last feature films she worked on. Since then, she has opted to dramatically alter the course of her life and career.Over the past few years, Haenel, 34, has become one of the most visible and committed faces of the #MeToo movement in France. In May, she wrote an open letter published in the influential French culture weekly Télérama to explain her absence from movie screens: “I decided to politicize my retirement from cinema to denounce the general complacency of the profession toward sexual aggressors and more generally the way in which this sphere collaborates with the mortal, ecocidal, racist order of the world such as it is.”She has, she told me, “a political understanding of the world, and my actions are consistent with it as much as possible. Calling someone radical is a way to say ‘She’s hysterical, she’s angry.’ I prefer coherent to radical.”I said that I had used the word in a positive way — to suggest bold choices that steered clear of the artistic mainstream. “I’m not annoyed with you,” Haenel said. “I’m reacting strongly, but it’s just to make myself clear.”Making herself clear is important to Haenel, who has an intense focus and frequently looked to the side as we talked, as if to better organize her thoughts away from an interlocutor’s gaze. She sometimes wrote down points she wanted to come back to later — and she did return to them.We were talking in a house on the bucolic campus of PS21: Performance Spaces for the 21st Century, in Chatham, N.Y., where Haenel was appearing in the director-choreographer Gisèle Vienne’s show “L’Étang.” The show comes next to New York City for performances at New York Live Arts, Saturday through Monday, as part of the Dance Reflections festival.By American theatrical standards, “L’Étang” (“The Pond”) is pretty close to radical, though. Based on a short play by the Swiss-German writer Robert Walser, the dance-theater piece locks Haenel and Julie Shanahan, a longtime member of Pina Bausch’s Tanztheater Wuppertal ensemble, in a helix of escalating tension performed in often excruciatingly slow motion, a tempo familiar to those who saw Vienne’s hypnotic “Crowd” last year at the Brooklyn Academy of Music.Haenel takes on multiple roles, most notably that of Fritz, an adolescent who fakes suicide to attract his mother’s attention, and his two siblings; Shanahan plays their parents. The atmosphere is somewhat hallucinatory — Vienne has cited David Lynch among her influences — but it requires consummate precision, both physical and emotional.“We worked a lot on trying to pierce through the surface of things, and that’s not something you can do alone,” Haenel said. “Among the people onstage, we tried to better understand what’s implied, to understand a person’s feelings. You start anticipating when a person is going to stop moving. That’s a kind of communication I feel very strongly with Julie. We don’t need to talk about it endlessly; I just feel how long she’s going to take to do something.”For Vienne, effort is an integral part of the process. “What I do is very technical from a choreographic and interpretive standpoint,” she said in Chatham. “This virtuosity is the result of a long physical and theoretical training — sociology, philosophy and politics are important to understanding what we’re in the process of building, and the formal choices we make as we create the piece.”This rigor and commitment suit Haenel, as she passionately pursues a path in which artistic goals are intertwined with politics and life, a dedication that coalesces in her work with Vienne.The two met in 2018, when they were on the admissions committee for the National Theater of Brittany’s acting school. Haenel participated in a workshop with prospective students led by Vienne. “I loved it,” she said. “The improvisation was related to her show ‘Crowd’ and involved developing slow motion as a new sense, like seeing or hearing, that would allow you to live or experience things differently.”Making herself clear: Haenel, who has retired from the movie business, has collaborated with Vienne on a few projects. “At the heart of ‘L’Étang,’” Haenel said, “is the issue of violence.”Lauren Lancaster for The New York TimesThe pair further explored that theme in “L’Étang,” which became their first official collaboration and, after a Covid 19-imposed delay, premiered in 2021. Over the course of our conversation, Haenel often circled back to what she referred to as de-hierarchization. In the show, for example, words, movement, music, sound and lighting all contribute to communicating information, feelings and emotions. This undermines the traditional place of text at the top of the theatrical pyramid, and makes us reconsider what carries meaning onstage.And “L’Étang” subverts the usual link between the performers’ body language and the way text is delivered — especially since the voices are often electronically distorted. (Adrien Michel did the sophisticated sound design.)“It’s about the friction between text and subtext,” Haenel said. She brought up an especially intense scene in which she and Shanahan are face to face. They barely move, but the effect is one of terrifying brutality. “Julie actually speaks very calmly, but for us it’s a crazy scene of aggression because there is a negation of the body language,” Haenel said, adding that something they explored with Vienne was dissociation. “We’ve achieved a level where we can have a body that looks almost stoned with a speeded-up voice.”The impact is intended to be as much political as it is aesthetic. “At the heart of ‘L’Étang’ is the issue of violence,” Haenel said, “and this violence is not about saying tough things, but about turning someone else’s speech into silence.”Haenel and Vienne’s partnership has bloomed since 2018. In August, they premiered a new show, “Extra Life,” also starring Theo Livesey and Katia Petrowick, at the prestigious Ruhrtriennale festival in Germany. They are also involved with public readings of work by Monique Wittig, the lesbian philosopher and activist who died in 2003 and has been enjoying a revival in France over the past few years. While in New York for “L’Étang,” Haenel is participating in a Wittig event on Wednesday at the Albertine bookstore, which its organizers conceived in collaboration with Vienne.“Talking about Monique Wittig is a political act of active memory creation,” said Haenel, who is trying to get new English translations of Wittig’s work off the ground. “I’d love to help her be read again in the United States, to be studied more.”Digging deep with Vienne and championing Wittig are of a piece for Haenel. “I’ve always tried to engage in a thinking process,” she said. “The idea is not so much to become better, but not to become calcified in an antiquated relationship to the world. What’s at stake is not whether that relationship is truer or not — I find the idea of a criteria of truth super-problematic — but whether it’s more alive or not. At least for me.” More